Bacterial degradation of lignin obtained from diferent methods

• Grant number: 25/04960-6
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2025
• End date: January 31, 2027
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Eleni Gomes
• Grantee: Adrian Gabriel Brandão Gouvêa
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil

Abstract

The increasing demand for sustainable alternatives to the production of chemical inputs has encouraged the use of lignocellulosic biomass, whether from cellulose and hemicellulose sugars or aromatics derived from lignin. Many of the latter have important uses in various industrial sectors, such as p-coumaric acid (p-CA), which can be biotransformed into value-added product, 4-vinylphenol (4-VF), used as a chemical building block in the production of biopolymers, allowing a biotechnological route to replace petroleum derivatives. This project is a continuation of the scientific initiation work (Fapesp grant, proc. No. 2024/07844-4) that aimed to isolate bacteria from sugarcane soil that are tolerant to liquor and capable of biotransforming p-CA to 4-VF. Samples of sugarcane soil were collected from three different harvested blocks and cultivated in a medium with alkaline hydrolysis liquor with a p-CA concentration of 1.1 g/L and at different dilutions. As a result, 11 bacterial strains tolerant to the compounds present in the hydrolyzed bagasse liquor were isolated, all capable of growing in 100% liquor concentrations. All strains demonstrated minimal growth capacity in p-CA concentrations of up to 0.9 g/L, but only Arthrobacter sp. AL 1.3 and Bacillus sp. TG 2.24 showed 4-VF production. Additionally, Bacillus cereus TD 4.31 was able to completely consume p-CA, although the generated products have not yet been identified. Based on these results, a project for the master's dissertation is proposed using these strains with better tolerance and consumption profiles of p-CA, which will be applied in media containing soluble lignin fragments extracted from sugarcane bagasse by alkaline hydrolysis and by hydrogenolysis. (AU)